31200040 has 32 divisors (see below), whose sum is σ = 71529480. Its totient is φ = 12243712.

The previous prime is 31200007. The next prime is 31200061. The reversal of 31200040 is 4000213.

It can be written as a sum of positive squares in 4 ways, for example, as 24940036 + 6260004 = 4994^2 + 2502^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5239 + ... + 9478.

Almost surely, 2^31200040 is an apocalyptic number.

It is an amenable number.

31200040 is an abundant number, since it is smaller than the sum of its proper divisors (40329440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31200040 is a wasteful number, since it uses less digits than its factorization.

31200040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14781 (or 14777 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 31200040 is about 5585.6995980808. The cubic root of 31200040 is about 314.8123178614.

Adding to 31200040 its reverse (4000213), we get a palindrome (35200253).

The spelling of 31200040 in words is "thirty-one million, two hundred thousand, forty".